CMSC INforMS: Genetic Link to Multiple Sclerosis Found

or the first time, scientists say they’ve discovered a genetic mutation linked to a rare type of multiple sclerosis, and they are hoping this discovery will eventually pave the way for new treatments for the disease.

Multiple sclerosis (MS) is a neurodegenerative disease in which the immune system attacks the myelin that protects nerve fibers, upsetting the flow of information between the brain and the body. It affects about 400,000 Americans and 2.5 million people worldwide, and in its more severe, progressive form, no good treatments are available.

Canadian researchers reviewed a large genetic database containing genetic material from almost 2,000 families, looking at families that had multiple cases of the disease, and performed gene sequencing to look for rare mutations present in all the members that had it. After identifying a suspected gene, they went back to the database and found the same gene mutation in another family with multiple cases of MS. All patients in these families with the mutation had the progressive form of MS.

Mice with this gene knocked out are known to have neurological problems, including a decrease in myelin production, adding to the evidence that this mutation is the one that may lead to this familial form of MS, the research team says.

In the cases of MS that have a hereditary component, until now researchers conducting genetic studies have found only weak associations between the risk of developing MS and particular gene variants. In contrast, people who carry the newly discovered mutation have a 70 percent chance of developing the disease, the team determined.

Although this genetic mutation is present in only about 1 in 1,000 people with MS, the team also found that common variants in the same gene are risk factors for progressive MS, the researchers say.

"Little is known about the biological processes that lead to the onset of the disease, and this discovery has massive amounts of potential for developing new treatments that tackle the underlying causes, not just the symptoms,” says Carles Vilariño-Güell, an assistant professor at the University of British Columbia in Vancouver, who is one of the senior authors of the study, which appears in Neuron.